JPS58207304A - Hot blast stove for blast furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is particularly suitable for use in blast furnaces having a refractory lining and a metal plate shell constructed by welding from a metal plate block and configured as a double shell with a small (partially hollow) double shell. Regarding hot air stoves.

Relatively high dome temperature up to 1600°C and 4ba
Modern hot air furnaces operating at hot air pressures up to r have the well-known problem of intergranular stress corrosion. In many cases, the metal plate envelope surrounding the refractory lining suffers early damage, so for reasons of operational safety the damage process can be suppressed or the hot blast furnace operated at lower dome temperatures, which impairs the economics of the equipment. stoppage of operations must be delayed. In general, with regard to intergranular stress corrosion, the generation of nitrates due to tensile stress is considered to be the origin of cracks on the metal surface.

DE 27 42 109, among other publications, also deals with the problem of stress corrosion, which, according to the description therein, is subject to thermal and mechanical stress. This is avoided by a protective outer skin that is elastically deformably welded to the inner wall of the outer skin.

Preferably, the protective shell is constructed from high-alloy special steel. This arrangement, by providing a protective shell on the inside with respect to the shell, is especially designed for new construction of hot-air stoves and cannot be implemented without great expense in hot-air stoves to be repaired.

The object of the present invention is to provide effective protection against stress corrosion by relatively simple measures using a double skin system, which can be retrofitted to already manufactured hot air stoves. Can be easily applied.

According to the invention, this problem is solved by the fact that the hot-blast stove has a double skin in whole or in part, which double skin has a metal sheet skin surrounding the refractory lining with spacing strips of 15 to 40 mm thick. and in the gap between both skins, a metal plate having a grain size of up to 811 and a thermal conductivity of 1.5 to 2.5 w/km (both 1.5 to 2.5 w/km).
The solution is to fill the dry material based on S'iC graphite. In this way, hot stove metal plate sheaths or parts of these metal plate sheaths that are at risk of intergranular stress corrosion can be protected preventively or subsequently improved by simple means. A double skin filled with dry material can be easily constructed with a conventional sheet metal skin. Therefore, in particular at least 1.7 Kg
/dFF? The relatively high thermal conductivity of the dry material, which is compacted to a uniform temperature range in the double skin, results in a structure that itself transfers forces and has as little thermal stress as possible.

The dry materials used for the double skin are SIC and graphite 80
Advantageously, it consists of 5% by weight Mg0 and 15% by weight BaSO4. It turns out that this composition is particularly advantageous in terms of operation.

Although the dry material protects the new skin from corrosive media,
For special protection of the inner surface of the outer metal plate skin, an acid-resistant paint based on epoxy resin is used and the outer metal is coated with an acid-resistant injection material made of epoxy resin with quartz aggregate, which is inserted between both skins. It is advantageous to cover the welded joints of the plate skin. The injection material is preferably 11% epoxy resin,
Preferably it consists of 13% specialty tar and 76% quartz with hardening agent.

A particularly advantageous configuration of the double skin is obtained if the spacing strips between the two skins are arranged laterally of the vertical weld joint of the outer skin and the injection material is placed between them. This greatly facilitates the filling process with various materials.

The spacing piece itself may consist of a U-section steel whose cross section is filled with injection material.

Since double skins often include a plurality of skin blocks arranged one above the other, for optimal configuration purposes it is preferable to equip the upper skin block with an exhaust and a closable filling tube, which Through the filling tube the block is filled only with injection material. This configuration proves to be particularly durable and economical.

The invention will be explained below with reference to the drawings.

In the drawings, reference numeral 1 denotes a metal plate outer shell, which connects the checker brick upright tube 2, the combustion upright tube 3, and the facing upright tube, and is a dome 4 of a hot air stove having the combustion upright tube on the outside.
and surround. The refractory lining sealed by the sheet metal skin 1 is not shown for reasons of simplicity. As is well known, the metal plate skin 1, which is composed of a skin block, is attached to the checker brick upright pipe 2, and the second outer skin 5 is attached to the combustion upright pipe 3 where the heating stage of the checker brick is fired. 2 with a gap of 6 in between.
Heavy hulls 1,5 are obtained. The outer skin 5 is composed of overlapping skin blocks 5a to 5e like the skin 1,
These skin blocks each consist of two semicircular parts 7 and 8 (FIG. 3).

All butt points are connected by welded joints 9 and 10 with welded strips 11 behind, and along the longitudinal sides of the vertical welded joints 9, spacing strips 12 of U-shaped cross section are attached to the skin 1. extend, these spacing strips define a gap 6 whose cross section is filled with the elastic material 13 to be set.

At the lower end, the outer skin 5 is supported via a horizontal weld joint 25 on a base section 14, which base section is connected to the inner skin 1.
and is welded to the annular bracket 15 of this inner skin. An annular bracket 17 and a top ring 16 welded to the skin l hold the upper end of the outer skin 5 via another horizontal weld joint 18 . There is a filling tube 20 which can be closed by a flange 19, and at the highest point of the gap 6, from which the filling open end of this tube 20 projects, there is a vent 21. The filling tube pieces 20 and the exhaust section 21 are arranged uniformly distributed around the outer skin 5.

In the gap 6 between the skins l and 5 two types of filling material 22
and 23, i.e., an injectable chemically setting acid-resistant filler material and a flowable dry filler material, of which acid-resistant injectable material 22 is placed along weld joints-9 and 10; On the other hand, dry material 23
fills the intermediate space.

The filling of both materials 22 and 23 begins with the bottom layer 2 made of flow material 22 after installing the first skin block 5a.
4, block by block, with the welding joint space between the spacing pieces 12 remaining open. Dry the material 2 using a vibrator onto the condensate backbend layer 24 until about 150 mm below the upper edge of the block 5a.
3 and then the vertical weld joint space between the spacing pieces 12 is filled with the injection material 22 up to the block height.

Next, the assembly of the second block 5b begins, and then the horizontal weld joint 1 joining the blocks 511 and 5b
The injection material 22 is injected up to 15011 above 0.

Once the injection material 22 has set, the process continues according to the criteria described above. The last block 5e assembled without spacing piece lz is only filled with injection material 22, the inflow of which injection material through filling tube piece 20 ends when the material flows out of exhaust port 21.

Advantageously, the injection material 22 and the material 13 of the spacing piece 12 are the same.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a part of the cross section of the metal plate outer skin of a hot air stove with a double outer skin area, and Fig. 2 shows a part of the length of part A indicated by the dashed line in Fig. 1. The enlarged view, FIG. 3, is a partial cross-sectional view of the double skin at the vertical weld joint of the outer skin. 1.5...Metal plate outer skin, 2...Checker brick upright cylinder, 6... Gap, 9. IO...welded joint, 12...
- Spacing piece, 22... Injection material, 23... Drying material Continued from page 1 0 Inventor Gerhard Zbert Sacht-Augustein, Federal Republic of Germany 2 Meiningen-Strasse 4

Claims (1)

[Scope of Claims] 1. In a hot blast furnace, in particular for a blast furnace, having a refractory lining and a metal plate skin constructed by welding from a metal plate block and configured at least partially as a hollow skin 21. Metal plate outer skin (1), the outer skin surrounding the fireproof lining
Attach the skin (5) to the second outer metal plate through a spacing piece (12) with a thickness of 15 to 4Q mm, and in the gap (6) between both skins (1, S), s A flowable dry material based on SiC graphite (particularly characterized in that it is formed by filling a 2:0 Hot blast furnace for blast furnace. 2 3i, C graphite material of dry material is 80% by weight,
5 wt.% MgO and 15 wt.% BaSo4
The hot air stove according to claim 1, characterized in that: is used. 3. The inner surface of the outer metal plate skin (5) has an acid-resistant coating based on epoxy resin, and the welded joints (9, 10) of this outer metal plate skin have a welding strip (11) on the inside,
Hot air according to claim 1, characterized in that it is coated with an acid-resistant injection material based on epoxy resin with quartz aggregate, which is placed in the gap (6) between both skins. Furnace. 4. The injection material consists of 11% epoxy resin, 13% special tar with hardener and 76% quartz, the proportion of quartz grain size is from 0 to 1111 equal to 38% by weight and as 9 particles equal to 38% by weight The hot air stove according to claim 3, characterized in that it has one or more layers. 5 Spacing piece provided in the gap between both outer skins (1
2) are provided on the sides of the vertical weld joints of the outer skin and between these spacings 1 to 1 the injection material (22
) A hot air stove according to one of claims 1 and 3, characterized in that: 6. Hot blast stove according to claim 5, characterized in that the spacing body (12) consists of a U-shaped steel section, the cross section being filled with injection material (22). 7 The outer skin block (5e) at the upper end is the exhaust part (21),
7. Hot-blast stove according to claim 1, characterized in that it has a closable filling tube piece (20) and only injection material (22) as filling.